Permits for most other exotics work that way.
Class I (really dangerous mammals and crocodilians): is all one permit but you need to meet the requirements seperately for unrelated species or possibly each species depending on interpretation.
Class II (fairly dangerous stiff): same deal, but fewer requirements.
Class III (relativly safe stuff): same deal, but almost no requirements other than applying, more requirements for some monkeys (I think, it's been a while since I looked into Class III).
Venomous reptiles are completely separate from the above classes.
You need 1000 hours of documented experience. Paid or unpaid doesn't matter, but good luck finding paid work doing it. This must be over a period of at least 1 year, but you're not likely to finish it any faster than that unless you get full time job doing it, which is not likely without already having the permit.
The next part is somewhat open to interpretation.
The regs say to dmonstrate 1000 hours working with the species you want to keep or similar species in the same "biological order" with similar husbandry. Well, most of us are interested in the biological order Squamata (all snakes, lizards and amphisbanians) and most snakes have pretty similar husbandry. If you've worked with a mamba, a cobra, a rattlesnake, a tree viper and a gila, you've about got it covered. My understanding is that (as someone else said) this is mostly a matter of them wanting to keep track of what you have in case they have to go deal with it. I don't believe there is any provision on the permit for restricting you to keeping specifically what you applied for, and you can then get any venomous reptile (with the exception of a few sea snakes that are covered under a separate "nuisence species" provision). I would reccomend that as long as you have to do the 1000 hours, you make it worth while and try to work with as many species as you can (but not at first). Handling certain species can be surprisingly different from related species even when the husbandry is basically identical.
The other big thing noone else has mentioned so far (and the reason I don't have a full permit yet) is that you need a secure snake room. That means not only locking to keep people out, but sealed to keep snakes in. Screen your vents and windows, plaster or caulk any cracks, and make sure there are no gaps around the door.
You need a serarate permit to sell venomous (or any reptile for that matter),
You need yet another permit to exhibit venomous.